Polymer coatings are often used to improve the effectiveness of adhesives. Such coatings can be referred to as primer coatings, and can be particularly effective at improving the effectiveness of adhesives on non-porous surfaces, such as glass, steel, aluminum, and ceramic materials.
U.S. Pat. No. 4,408,012 describes moisture-activated adhesives useful for adhering a solar film to glass. These adhesives comprise the reaction product of a gamma-isocyanatopropyltriethoxy silane containing a free isocyanate group and a thermoplastic polyester.
U.S. Pat. No. 4,146,585 discloses moisture-curable compositions described as polymeric adhesion promoters. These compositions comprise a silane-grafted binary copolymer or terpolymer that is prepared by reacting an isocyanato-functional organosilane containing from 1 to 3 silicon-bonded hydrolyzable groups with a hydroxy-functional copolymer or terpolymer.
Primer coatings are often used in the automotive industry on glass windshields to improve the effectiveness of the adhesive sealants used to adhere the windshield to the automotive body. In modern automotive design construction, the windshield is an integral part of the structural integrity of the vehicle. Thus, it is critical that the windshield sealant securely bond the windshield to the vehicle body panels. Accordingly, the adhesive bond between the windshield and the automotive body must meet highly rigorous performance standards with regard to weathering, and resistance to heat, ultraviolet radiation, and moisture. With regard to heat, it is desirable that the adhesive bond resist temperatures of up to 88.degree.C.
One glass primer that has been so utilized in the automotive industry is a silane-terminated polyester polyurethane consisting of polyester blocks linked together through urethane linkages. However, neither this primer nor the above-described prior art compositions provide as high a degree of resistance to weathering, heat, UV radiation, and moisture as is often desired. It is therefore an object of the invention to provide a polymer that can be effectively used in a primer coating composition, and that has a high a degree of resistance to weathering, heat, UV radiation, and moisture.